A light emitting device using a light-emitting diode (LED) is widely utilized for lighting devices such as a backlight of a liquid crystal display device, a signal device, various switches, a lamp for vehicle, and a general lighting. In particular, a white light-emitting LED lamp in which the LED and a phosphor are combined attracts attention as an alternative to an incandescent light bulb, and its development is advanced rapidly. As a light bulb having the LED lamp applied thereto (described as an LED light bulb, hereinafter), for example, there is known one having an integrated lamp structure in which to a base portion having a light bulb cap provided thereon, a globe is attached, LED chips are disposed in the globe, and a lighting circuit for the LED chips is provided in the base portion.
To a conventional LED light bulb, there is applied a combination of a blue light-emitting LED chip (a blue LED) and a yellow phosphor that absorbs blue light emitted from the blue LED to emit yellow light (a YAG phosphor or the like), and by a mixed color of the blue light from the blue LED and the yellow light from the yellow phosphor, white light is obtained. The LED light bulb having the blue LED and the yellow phosphor combined therein has a characteristic such that brightness is likely to be secured. The white light based on the mixed color of the blue light from the blue LED and the yellow light from the yellow phosphor deteriorates in color rendering property evaluated in an average color rendering index (Ra) and the like.
The conventional LED light bulb having the blue LED and the yellow phosphor combined therein has a light distribution biased toward a blue component and a yellow component, and a red component is insufficient. For this reason, reflected light when an object is seen under the light from the LED light bulb differs from a natural color when it is seen under sunlight. Further, in the conventional LED light bulb, the light radiated from the blue LED is used for the generation of white light, so that it is difficult to uniformize the luminance of the entire light bulb. This makes it difficult to decrease dazzle and local over-brightness of the light bulb, namely what is called glare.